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See detailErosion and sedimentation issues in a hydropower project: assessing impacts and opportunities
Dewals, Benjamin ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Schüttrumpf, Holger (Ed.) Offene Gewässer: Strahlwirkung, Fischaufstieg, Fischabstieg, Sedimente, Schadstoffe (2015, January 09)

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See detailOptimal Enforcement of Competition Policy: The Commitments Procedure under Uncertainty
Gautier, Axel ULg

Scientific conference (2015, January 08)

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See detailSymmetry breaking patterns in 3HDM
Ivanov, Igor ULg; Nishi, Celso

in Journal of High Energy Physics [=JHEP] (2015), 15

An attractive feature of New Physics models with multiple Higgs fields is that they are equipped with discrete symmetry groups in the Higgs and flavour sectors. These symmetry groups are often broken at ... [more ▼]

An attractive feature of New Physics models with multiple Higgs fields is that they are equipped with discrete symmetry groups in the Higgs and flavour sectors. These symmetry groups are often broken at the global minimum of the Higgs potential, either completely or to a proper subgroup, with certain phenomenological consequences. Here, we systematically explore these symmetry breaking patterns in the scalar sector of the three-Higgs-doublet model (3HDM). We use the full list of discrete symmetry groups allowed in 3HDM, and for each group we find all possible ways it can break by the Higgs vacuum expectation value alignment. We also discuss the interplay between these symmetry groups and various forms of CP-violation in the scalar sector of 3HDM. Not only do our results solve the problem for 3HDM, but they also hint at several general features in multi-scalar sectors. [less ▲]

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See detailQualité diagnostique et efficacité d'un système en ligne entrainant à la résolution de problèmes complexes en physique
Marique, Pierre-Xavier ULg; Jacquet, Maud ULg; Georges, François ULg et al

Conference (2015, January 08)

Dans le cadre de projets de lutte contre l’échec en bachelier, le LabSET et des enseignants de physique de l'Université de Liège ont développé un dispositif en ligne d’entraînement à la résolution de ... [more ▼]

Dans le cadre de projets de lutte contre l’échec en bachelier, le LabSET et des enseignants de physique de l'Université de Liège ont développé un dispositif en ligne d’entraînement à la résolution de problèmes complexes en physique. La recherche porte d’une part sur le diagnostic de la maîtrise des processus cognitifs à mobiliser pour résoudre des problèmes de physique et d’autre part sur le lien entre l’entrainement effectif en ligne et la performance des étudiants lors de la résolution de problèmes à l'examen. Les analyses reposent sur étude menée auprès de 876 étudiants inscrits en premier bachelier médecine. Elles ont été effectuées sur bases des données subjectives (auto-évaluation du processus et du produit) et objectives (nombre de connexions aux exercices en ligne, résultats de maîtrise des questions spécifiques aux processus cognitifs étudiés, taux de réussite et notes aux examens). A l’issue de la recherche, nous constatons que c’est le processus d’analyse. Près de 50 % des étudiants en sont conscients. Bien que la force d'association soit de faible à moyenne, une dépendance est observée entre travail en ligne et réussite aux problèmes présentés à l’examen de juin. Les notes des étudiants ayant travaillé en ligne sont supérieures à celles des étudiants n’ayant réalisé aucun problème en ligne. Cependant, étant donné que les étudiants ayant réussi la physique sont aussi ceux ayant réussi des autres matières scientifiques, il est difficile d'établir un rapport de causalité entre travail en ligne et performances. [less ▲]

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See detailQuelle voiture pour demain? Existence des solutions alternatives et évolution nécessaire des systèmes de transport collectifs et individuels
Duysinx, Pierre ULg

Scientific conference (2015, January 08)

Face aux défis du 21ème siècle, il est légitime de s’interroger sur l’existence et l’évolution nécessaire des systèmes de transports collectifs et individuels. L’exposé présente les lignes de forces qui ... [more ▼]

Face aux défis du 21ème siècle, il est légitime de s’interroger sur l’existence et l’évolution nécessaire des systèmes de transports collectifs et individuels. L’exposé présente les lignes de forces qui guident l’évolution des véhicules afin de les rendre plus soutenables : écologiques, économiques et socialement acceptables à l’horizon 2030-2050. [less ▲]

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See detailLa réforme des soins de santé mentale en Belgique: pas complètement convergents, mais concrètement interdépendants
Thunus, Sophie ULg

Conference (2015, January 08)

Dans cet article, nous retracerons d’abord les grandes lignes des évolutions des associations d’usagers et de proches en santé mentale, en Europe et en Belgique. Ensuite, nous présenterons une ... [more ▼]

Dans cet article, nous retracerons d’abord les grandes lignes des évolutions des associations d’usagers et de proches en santé mentale, en Europe et en Belgique. Ensuite, nous présenterons une expérimentation politique dans le champ de la santé mentale en Belgique, qui a été l’occasion, pour les associations d’usagers et de proches, d’institutionnaliser leur participation. A cette occasion, nous évoquerons les motifs politiques à l’origine du projet de participation (acte 1) confié par les autorités publiques belges aux associations, ses modalités, et son implémentation au sein d’un dispositif d’action publique impliquant également des experts professionnels et scientifiques. Dans un troisième temps, nous nous intéresserons à la poursuite du projet participation dans le cadre de la réforme actuelle de la santé mentale et de la psychiatrie. Nous décrirons les modalités d’implémentation du projet (acte 2) et les nouveaux défis qui se posent aux associations, au fur-et-à-mesure de l’augmentation et de la visibilité accrue de leur participation aux niveaux institutionnels et politiques. En conclusion, nous soulignerons le caractère contingent de l’émergence et de la stabilisation de la participation en Belgique. Nous verrons que ce caractère contingent est à l’origine de fortes interdépendances entre le développement de la participation, des projets politiques spécifiques et trajectoires individuelles particulières. Cette interdépendance génère à son tour des enjeux spécifiques, pour les associations et les représentants des usagers, en termes identitaires et de légitimité. Nous soulignerons en outre le caractère incrémental du processus par lequel les associations stabilisent leur discours, leur méthodologie et leur intervention concrète dans la prise de décision aux niveaux macro et micro. A cet égard, mettrons en évidence l’importance de la production continue de documents (recommandations, questionnaires, …) stabilisant les éléments-clé de ce discours et permettant aux experts par le vécu de le porter en différents endroits, au sein des institutions des soins et dans la sphère politique. Finalement, nous envisagerons l’hypothèse de la professionnalisation des représentant(e)s des associations et des représentants des usagers, tout en soulignant les enjeux personnels et structurels associés à cette professionnalisation. [less ▲]

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See detailInvariant games and non-homogeneous Beatty sequences
Rigo, Michel ULg

Scientific conference (2015, January 08)

The aim of this talk is to introduce some notions arising in combinatorial game theory and make the connection with combinatorics on words. We characterize all pairs of complementary non-homogenous Beatty ... [more ▼]

The aim of this talk is to introduce some notions arising in combinatorial game theory and make the connection with combinatorics on words. We characterize all pairs of complementary non-homogenous Beatty sequences (A_n)n≥0 and (B_n)n≥0 for which there exists an invariant game having exactly {(A_n,B_n)∣n≥0}∪{(B_n,A_n)∣n≥0} as set of P-positions. Using the notion of Sturmian word and tools arising in symbolic dynamics and combinatorics on words, this characterization can be translated to a decision procedure relying only on a few algebraic tests about algebraicity or rational independence. Given any four real numbers defining the two sequences, up to these tests, we can therefore decide whether or not such an invariant game exists. [less ▲]

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See detailAutour du sujet défait
Vrancken, Didier ULg

Conference (2015, January 07)

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See detailRecent summer Arctic atmospheric circulation anomalies in a historical perspective
Belleflamme, Alexandre ULg; Fettweis, Xavier ULg; Erpicum, Michel ULg

in Cryosphere (The) (2015), 9

A significant increase in the summertime occurrence of a high pressure area over the Beaufort Sea, the Canadian Arctic Archipelago, and Greenland has been observed since the beginning of the 2000s, and ... [more ▼]

A significant increase in the summertime occurrence of a high pressure area over the Beaufort Sea, the Canadian Arctic Archipelago, and Greenland has been observed since the beginning of the 2000s, and particularly between 2007 and 2012. These circulation anomalies are likely partly responsible for the enhanced Greenland ice sheet melt as well as the Arctic sea ice loss observed since 2007. Therefore, it is interesting to analyse whether similar conditions might have happened since the late 19th century over the Arctic region. We have used an atmospheric circulation type classification based on daily mean sea level pressure and 500 hPa geopotential height data from five reanalysis data sets (ERA-Interim, ERA-40, NCEP/NCAR, ERA-20C, and 20CRv2) to put the recent circulation anomalies in perspective with the atmospheric circulation variability since 1871. We found that circulation conditions similar to 2007–2012 have occurred in the past, despite a higher uncertainty of the reconstructed circulation before 1940. For example, only ERA-20C shows circulation anomalies that could explain the 1920–1930 summertime Greenland warming, in contrast to 20CRv2. While the recent anomalies exceed by a factor of 2 the interannual variability of the atmospheric circulation of the Arctic region, their origin (natural variability or global warming) remains debatable. [less ▲]

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See detailContributions to combinatorics on words in an abelian context and covering problems in graphs
Vandomme, Elise ULg

Doctoral thesis (2015)

This thesis dissertation is divided into two (distinct but connected) parts that reflect the joint PhD. We study and we solve several questions regarding on the one hand combinatorics on words in an ... [more ▼]

This thesis dissertation is divided into two (distinct but connected) parts that reflect the joint PhD. We study and we solve several questions regarding on the one hand combinatorics on words in an abelian context and on the other hand covering problems in graphs. Each particular problem is the topic of a chapter. In combinatorics on words, the first problem considered focuses on the 2-regularity of sequences in the sense of Allouche and Shallit. We prove that a sequence satisfying a certain symmetry property is 2-regular. Then we apply this theorem to show that the 2-abelian complexity functions of the Thue--Morse word and the period-doubling word are 2-regular. The computation and arguments leading to these results fit into a quite general scheme that we hope can be used again to prove additional regularity results. The second question concerns the notion of return words up to abelian equivalence, introduced by Puzynina and Zamboni. We obtain a characterization of Sturmian words with non-zero intercept in terms of the finiteness of the set of abelian return words to all prefixes. We describe this set of abelian returns for the Fibonacci word but also for the Thue--Morse word (which is not Sturmian). We investigate the relationship existing between the abelian complexity and the finiteness of this set. In graph theory, the first problem considered deals with identifying codes in graphs. These codes were introduced by Karpovsky, Chakrabarty and Levitin to model fault-diagnosis in multiprocessor systems. The ratio between the optimal size of an identifying code and the optimal size of a fractional relaxation of an identifying code is between 1 and 2 ln(|V|)+1 where V is the vertex set of the graph. We focus on vertex-transitive graphs, since we can compute the exact fractional solution for them. We exhibit infinite families, called generalized quadrangles, of vertex-transitive graphs with integer and fractional identifying codes of order |V|^a with a in {1/4,1/3,2/5}. The second problem concerns (r,a,b)-covering codes of the infinite grid already studied by Axenovich and Puzynina. We introduce the notion of constant 2-labellings of weighted graphs and study them in four particular weighted cycles. We present a method to link these labellings with covering codes. Finally, we determine the precise values of the constants a and b of any (r,a,b)-covering code of the infinite grid with |a-b|>4. This is an extension of a theorem of Axenovich. [less ▲]

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See detailDirect detection of Aspergillus and azole resistance of Aspergillus fumigatus on broncho-alveolar lavage fluid. Validation of a new Aspergillus real-time PCR
Chong, Ga-Lai; Van de Sande, Wendy; Dingemans, Gijs et al

in Journal of Clinical Microbiology (2015)

Introduction Azole resistance in Aspergillus fumigatus is increasingly reported. We describe the validation of AsperGenius® , a new multiplex real-time polymerase chain reaction (PCR) assay consisting of ... [more ▼]

Introduction Azole resistance in Aspergillus fumigatus is increasingly reported. We describe the validation of AsperGenius® , a new multiplex real-time polymerase chain reaction (PCR) assay consisting of two multiplex real-time PCRs: one which identifies the clinically relevant Aspergillus species, and one which detects the TR34, L98H, T289A, Y121F mutations in CYP51A and differentiates susceptible from resistant A. fumigatus strains. Methods The diagnostic performance was tested on 37 bronchoalveolar lavage (BAL) samples from haematology patients and on 40 BAL samples from intensive care unit (ICU) patients using BAL galactomannan ≥1.0 or positive culture as the gold standard for the presence of Aspergillus. Results In the haematology and ICU groups combined, there were 22 BAL samples with IA (2 proven, 9 probable and 11 non-classifiable). Nineteen of the 22 BAL samples were positive according to the gold standard. The optimal cycle threshold value for the presence of Aspergillus was <36. Sixteen of the 19 BAL samples had a positive PCR (2 Aspergillus species and 14 A. fumigatus). This resulted in a sensitivity, specificity, positive and negative predictive value of 88.9%, 89.3%, 72.7% and 96.2% for the haematology group and 80.0%, 93.3%, 80.0% and 93.3% in the ICU group, respectively. The CYP51A real-time PCR confirmed 12 wildtype and 2 resistant strains (1 TR34/L98H and 1 TR46/Y121F/T289A mutant). Conclusion The AsperGenius® multiplex real-time PCR allows for a sensitive and fast detection of Aspergillus species directly in BAL samples. More importantly, this assay detects and differentiates wildtype from resistant strains even if BAL cultures remained negative. [less ▲]

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See detailAbsence of Varicella Zoster Virus Reactivation after Infliximab Administration for Plaque Psoriasis
EL HAYDERI, Lara ULg; BONTEMS, Sébastien ULg; MEEX, Cécile ULg et al

in Dermatology (2015)

Background: Herpes zoster (HZ) in patients receiving tumor necrosis factor (TNF) antagonists may be more severe and the incidence seems increased. The influence of TNF antagonists on varicella zoster ... [more ▼]

Background: Herpes zoster (HZ) in patients receiving tumor necrosis factor (TNF) antagonists may be more severe and the incidence seems increased. The influence of TNF antagonists on varicella zoster virus (VZV) reactivation is unknown. Objective: To prospectively search in a pilot study for VZV DNA in sequential blood samples before and after infliximab administration. Setting: University medical center. Subjects and Methods: Blood samples of six patients with longstanding and severe plaque psoriasis were taken on day 1 (before infliximab administration) and on days 2, 7, 21 and 42 for the determination of VZV viremia by ORF21 real-time polymerase chain reaction. Patients with varicella, HZ and normal subjects were included as controls. Results: None of the six patients presented VZV viremia at any of the time points. Highload viremia was present during varicella, low-load viremia in some HZ patients and no viremia in the control patients. Limitations: Small number of patients. Conclusions: In this pilot study, infliximab did not reactivate VZV and did not induce subclinical VZV viremia. [less ▲]

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See detailLa période hollandaise en Belgique
Brüll, Christoph ULg

Conference given outside the academic context (2015)

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See detailEnvironmental changes and the city
Ozer, Pierre ULg

Scientific conference (2015, January 06)

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See detailStable climate and surface mass balance in Svalbard over 1979–2013 despite the Arctic warming
Lang, Charlotte ULg; Fettweis, Xavier ULg; Erpicum, Michel ULg

in Cryosphere (The) (2015), 9

With the help of the regional climate model MAR (Modèle Atmosphérique Régional) forced by the ERA-Interim reanalysis (MARERA) and the MIROC5 (Model for Interdisciplinary Research on Climate) global model ... [more ▼]

With the help of the regional climate model MAR (Modèle Atmosphérique Régional) forced by the ERA-Interim reanalysis (MARERA) and the MIROC5 (Model for Interdisciplinary Research on Climate) global model (MARMIROC5) from the CMIP5 (Coupled Model Intercomparison Project) database, we have modelled the climate and surface mass balance of Svalbard at a 10 km resolution over 1979–2013. The integrated total surface mass balance (SMB) over Svalbard modelled by MARERA is negative (−1.6 Gt yr−1) with a large interannual variability (7.1 Gt) but, unlike over Greenland, there has been no acceleration of the surface melt over the past 35 years because of the recent change in atmospheric circulation bringing northwesterly flows in summer over Svalbard, contrasting the recent observed Arctic warming. However, in 2013, the atmospheric circulation changed to a south–southwesterly flow over Svalbard causing record melt, SMB (−20.4 Gt yr−1) and summer temperature. MIROC5 is significantly colder than ERA-Interim over 1980–2005 but MARMIROC5 is able to improve the near-surface MIROC5 results by simulating not significant SMB differences with MARERA over 1980–2005. On the other hand, MIROC5 does not represent the recent atmospheric circulation shift in summer and induces in MARMIROC5 a significant trend of decreasing SMB (−0.6 Gt yr−2) over 1980–2005. [less ▲]

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See detailIchtyofaune du bassin du fleuve Mono (Bénin et Togo): diversité, écologie et impacts anthropiques
Lederoun, Djiman ULg

Doctoral thesis (2015)

This study has three main objectives: (1) to obtain an inventory of the ichthyofauna of the Mono River that is as complete as possible; (2) to study the ecology of this ichthyofauna; and (3) to document ... [more ▼]

This study has three main objectives: (1) to obtain an inventory of the ichthyofauna of the Mono River that is as complete as possible; (2) to study the ecology of this ichthyofauna; and (3) to document the impact of fishing on the exploited stocks based on two targeted species. The inventory was made by compiling the literature, by studying collections of museums and of other institutions and by several sampling campaigns, conducted between February 2011 and March 2014. This resulted in an inventory of 91 fish species belonging to 67 genera, 42 families and 14 orders. The Perciformes (31 species), Siluriformes (18), Osteoglossiformes (10), Cypriniformes (9) and Characiformes (9) are the most diverse families in the Mono River Basin. The most species-rich families are the Cichlidae (9 espèces), Cyprinidae (9), Mormyridae (7), Clariidae (7) and Alestidae (6). Twenty-nine species, of which 7 of freshwater and 22 of marine or estuarine origin have been added to the ichtyofauna as known before this study. Nine species present in museum collections and three species only known from the literature have not been collected again. Several taxonomic problems have been encountered. Two of these cases were studied in depth. Foremost, the taxonomic status of Brycinus leuciscus and B. luteus (Alestiidae, Characiformes) was revised based on specimens originating from the complete distribution range of the two nominal species. This allowed us to synonymise the two species, with Brycinus leuciscus as senior synonym. The latter has been erroneously mentioned from the Mono River. Our results, however, confirmed the presence of two phenotypes, i.e. one with and one without a pre-dorsal hump, which was mentioned in the literature as intra-specific variation in B. leuciscus. A comparative study comparing specimens belonging to 'Barbus' nigeriensis (Cyprinidae, Cypriniformes) of the Mono Basin with those originating from the basins of the Volta, the Ogun et the Niger revealed the presence of a new species, described as Barbus "Vandewalle", a Volta Basin endemic. An indentification key of the different families, genera and species from the Mono Basin is presented. For the ecological study, two seasonal sampling campaigns were performed (from December to mid-March and from mid-July to mid-September) in 2012 and 2013 using gill nets of different mesh-size (10, 12, 17, 20 et 22 mm knot to knot). Sampling was performed at 10 sampling sites that were located upstream and downstream of the Adjarala Falls (the site of a planned hydroelectric plant, 100 km upstream of that of Nangbéto) and upstream and downstream of the dam at Nangbéto. Seventeen physico-chemical and environmental variables were taken at these sites. The ordination of the sampling sites in relation to their values for the physico-chemical, environmental variables and to their fish assemblages was studied using a non-linear method: the self organising map (SOM). The samples were scattered in four groups in function of their physico-chemical and environmental variables. The distance to the source, height of the canopy, rocks, coverage of the canopy, altitude, gravel, mud, sand, water velocity and dissolved oxygen were the most discriminating factors for the obtained groups. The zone of the Adjarala, where a new dam will be constructed, differs by its rocky substrate, the velocity of the water and the relatively high amount of dissolved oxygen. For the ichthyofauna, the SOM suggest a structuring in three groups. Our results oppose the tendency to homogeny in the middle course of rivers, which is probably due to the presence of the dam at Nangbéto. A significant correlation was found between the distribution of the species and the physico-chemical and environmental parameters. The distance to the source, altitude, forested river banks, height of the canopy, velocity of the water, conductivity, transparency and pH were the parameters that explained the distribution of the fish community best. The level of disturbance of the ecosystem, which was studied using the Abundance Biomass Comparison (ABC) showed that the zones at and near the dam at Nangbéto were the most stressed. A length-weight and length-length key was designed for the first time for the 37 species that were the most abundant in the catches. This was done in order to improve the quality of the fisheries statistics collected by fisheries officers on the scale of the basin. The analysis of the allometric coefficient b of the length-weight relation showed that the majority of the fishes had an allometric growth. The condition factor calculated in order to estimate the amount of flesh on the fish showed that the environment was heavily disturbed. To conclude, from the results of the study on the impact of the fisheries on targeted species, it became clear that the population of Sarotherodon melanotheron melanotheron is over-exploited at Lake Toho. At Lakes Doukon and Togbadji, on the other hand, an under-exploitation of the population of S. galilaeus galilaeus was observed. The latter illustrates the possibility of sustainable management even in the presence of intensive fishing pressure. As, in this thesis, several cases of anthropogenic impacts were identified, a regular surveillance programme will be paramount in order to preserve the ichthyological diversity of the Mono River Basin. [less ▲]

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See detailClostridium difficile from food and surface samples in a Belgian nursing home: An unlikely source of contamination
Rodriguez Diaz, Cristina ULg; Korsak Koulagenko, Nicolas ULg; Taminiau, Bernard ULg et al

in Anaerobe (2015), 32

This study investigates the contamination of foods and surfaces with Clostridium difficile in a single nursing home. C. difficile PCR-ribotype 078 was found in one food sample and in none of the tested ... [more ▼]

This study investigates the contamination of foods and surfaces with Clostridium difficile in a single nursing home. C. difficile PCR-ribotype 078 was found in one food sample and in none of the tested surfaces. These results indicate that food and surfaces are an unlikely source of C. difficile infection in this setting. [less ▲]

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See detailAssociation of Cerebrospinal Fluid Prion Protein Levels and the Distinction Between Alzheimer Disease and Creutzfeldt-Jakob Disease
Dorey, Aline; Tholance, Yannick; Vighetto, Alain et al

in JAMA Neurology (2015)

IMPORTANCE Although typical forms of Alzheimer disease (AD) and Creutzfeldt-Jakob disease (CJD) are clinically distinguishable, atypical AD phenotypesmay pose a diagnostic challenge. The major biological ... [more ▼]

IMPORTANCE Although typical forms of Alzheimer disease (AD) and Creutzfeldt-Jakob disease (CJD) are clinically distinguishable, atypical AD phenotypesmay pose a diagnostic challenge. The major biological diagnostic biomarker for identifying CJD, 14-3-3 protein in cerebrospinal fluid (CSF), unfortunately lacks specificity when confronting a rapid dementia presentation. OBJECTIVE To assess the relevance of total CSF prion protein (t-PrP) levels in the differential biological diagnosis between atypical AD phenotypes and CJD. DESIGN, SETTING, AND PARTICIPANTS A retrospective study in an autopsy-confirmed cohort of 82 patients was performed to evaluate the relevance of CSF t-PrP to distinguish 30 definite cases of AD from 52 definite cases of CJD. Next, CSF t-PrP concentration was measured in a cohort of 104 patients including 55 patients with probable AD, 26 with probable sporadic CJD, and 23 control patients for whom 14-3-3 protein, total tau, phosphorylated tau 181 (P-tau181), and Aβ1-42 were available.We investigated 46 patients diagnosed as having probable AD who presented atypical phenotypes. A diagnosis strategy was proposed to classify atypical AD phenotypes with suspicion of CJD based on a decision tree combining CSF biomarkers. MAIN OUTCOMES AND MEASURES We determined CSF t-PrP levels for all patients.We calculated the ratio of total tau and P-tau181 and determined the diagnostic accuracy of each biomarker alone or in combination.We calculated the misclassification rate for each biomarker that corresponded to the percentage of patients within the group of atypical AD phenotypes wrongly classified as CJD. RESULTS In patients with CJD, CSF t-PrP concentrations were decreased compared with control participants and patients with AD. When considering the differential diagnosis of CJD compared with atypical AD phenotypes, CSF t-PrP determination reached 82.1%sensitivity and 91.3%specificity. The misclassification rate of atypical AD phenotypes decreased from 43.5%, obtained when using the CSF 14-3-3 protein determination alone, to only 4.3%when calculating the ratio total tau/(P-tau181 × t-PrP). The proposed classification tree permitted correct classification of 98.4%of the patients. CONCLUSIONS AND RELEVANCE For unusual phenotypes of AD, especially cases presenting with a biological ambiguity suggesting CJD, determination of CSF t-PrP levels increased diagnostic accuracy. The use of CSF t-PrP levels may be beneficial in clinical practice in [less ▲]

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See detailHigh-density mapping of the MHC identifies a shared role for HLA-DRB1*01:03 in inflammatory bowel diseases and heterozygous advantage in ulcerative colitis.
Goyette, Philippe; Boucher, Gabrielle; Mallon, Dermot et al

in Nature Genetics (2015), 47(2), 172-9

Genome-wide association studies of the related chronic inflammatory bowel diseases (IBD) known as Crohn's disease and ulcerative colitis have shown strong evidence of association to the major ... [more ▼]

Genome-wide association studies of the related chronic inflammatory bowel diseases (IBD) known as Crohn's disease and ulcerative colitis have shown strong evidence of association to the major histocompatibility complex (MHC). This region encodes a large number of immunological candidates, including the antigen-presenting classical human leukocyte antigen (HLA) molecules. Studies in IBD have indicated that multiple independent associations exist at HLA and non-HLA genes, but they have lacked the statistical power to define the architecture of association and causal alleles. To address this, we performed high-density SNP typing of the MHC in >32,000 individuals with IBD, implicating multiple HLA alleles, with a primary role for HLA-DRB1*01:03 in both Crohn's disease and ulcerative colitis. Noteworthy differences were observed between these diseases, including a predominant role for class II HLA variants and heterozygous advantage observed in ulcerative colitis, suggesting an important role of the adaptive immune response in the colonic environment in the pathogenesis of IBD. [less ▲]

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